[Home](./index.md) > [rc-js-util](./rc-js-util.md) > [equalityAreConsistentlyDefined](./rc-js-util.equalityareconsistentlydefined.md) ## equalityAreConsistentlyDefined() function Returns true if both `A` and `B` are both null, undefined or 'defined'. Defined is not null and not undefined. **Signature:** ```typescript export declare function equalityAreConsistentlyDefined(a: T | undefined | null, b: T | undefined | null): boolean; ``` ## Parameters

Parameter	Type	Description
a	T \| undefined \| null
b	T \| undefined \| null

**Returns:** boolean ## Remarks See [equalityAreConsistentlyDefined()](./rc-js-util.equalityareconsistentlydefined.md).